1. Field of the Invention
The present invention relates to a rotating electric machine to which an inverter is integrally assembled and, more particularly, to a rotating electric machine that contains therein a control device to be installed on electric vehicles, hybrid vehicles, and idle-stop vehicles. The invention also relates to a manufacturing method of the rotating electric machine.
2. Description of the Related Art
In conventional rotating electric machines to which an inverter is integrally assembled, there is the one in which switching elements are mounted on a metal board, being an aluminum substrate on which a metal pattern is formed via an insulating layer. Further, to make an electrical connection between the metal board and a control board, there is provided a connection member formed by enveloped casting of the metal pattern with resin. One of connection terminals of the connection member is connected to a land space of the metal board, and the other connection terminal is connected to a through hole of the control board. In addition, the metal board is fixed to a heat sink via grease. (See FIG. 1 of the Japanese Patent Publication (unexamined) No. 254359/2004)
In the conventional rotating electric machines, a metal pattern on the metal board is formed in a planar state, so that a large mounting area is required when including the area for, e.g., resist. Furthermore, there has to be provided a space for mounting parts on the metal board, and other space for soldering the connection terminals. Moreover, the metal board and the control board are connected via the terminals of the connection member, a connection work is complicated, and a space for connecting terminals and boards together is also needed. Thus, the entire device gets larger, as well as a problem exists in high manufacturing costs.
Particularly in the rotating electric machine to which an inverter is integrally assembled, to contain an inverter in the rotating electric machine, it is necessary to downsize a control device. A large number of parts or the mounting space comes to be a cause of preventing the downsizing.
Meanwhile, the control device of the rotating electric machine is located near an engine, and taking into consideration the heat generation of switching elements, the control device is operated under extremely high-temperature conditions. Therefore, a large amount of heat is transferred to an insulating layer on the metal board, and thus a problem exists in that the metal board and the insulating layer are separated.
In the conventional structures using an expensive metal board or grease, there has to be provided an insulating layer of the board having insulating properties or grease, resulting in larger manufacturing costs of the rotating electric machine.